Wallpaper size bubbling

[MidsTW]

Just put the wallpaper size on the walls and noticed some very small bubbles.

The wall is a mixture of new plaster, filler and old emulsion. The bubbles seem to be in the old emulsion.

I have done 2 other rooms this way and never noticed a problem. Maybe just didn't see them before.

Any ideas guys? Hoping they will shrink back when it dries.

 

[MidsTW]

I can understand it being a problem I'm just painting but should I be alright papering?